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MW 9 - Integrated Flux Nebula in the constellation Bird of
Paradise (Apus) and the galaxies IC 4633 and IC 4535 |
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Short description:
In the constellation Apus (the Bird of Paradise)
there are large molecular clouds (Integrated Flux Nebula (IFN), they lie far
above the disk plane of our galaxy near the southern celestial pole. Integrated
Flux Nebulae are relatively newly defined astronomical objects, the term IFN
was coined by the American amateur American amateur astronomer Steve Mandel.
They are extremely weak luminous, cold molecular cooling clouds of the
interstellar medium and are consist mainly of the elements hydrogen, carbon,
carbon monoxide carbon monoxide and other elements. They are conspicuously
concentrated in the towards the northern and southern celestial
poles.
Compared to the typical and well-known gas nebulae within the
plane of our Milky Way (reflection nebulae, H-II regions), IFNs lie outside the
disc centre of the Galaxy. And unlike most nebulae in the Galactic plane, they
do not reflect, scatter or ionise due to the radiation of individual stars or
star clusters, but due to the energy of the integrated energy flow of ALL stars
in the Milky Way. IFNs have been little studied because they are extremely
faint and do not stand out against the noise of the sky background in a less
than perfect dark sky.
The Bird of Paradise
is one of the constellations introduced at the end of the 16th century by the
Dutch sailors Pieter Dirkszoon Keyser and Frederick de Houtman. It is not known
whether the sailors "created" the constellation or took it over from the
inhabitants of the South Seas. It is an inconspicuous constellation near the
southern celestial pole, only two stars are brighter than 4th magnitude. Johann
Bayer included the constellation under the name "Avis Indica" (Indian Bird) in
his celestial atlas Uranometria published in 1603. |
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Our
image shows a large part of MW 9 (Mandel/Wilson)
in the constellation of the Bird of Paradise. The north-eastern part (top left
of the image) is reminiscent of an approaching, large bird of prey. At the
bottom right of the image are two brighter galaxies, IC
4633 and IC 4635, both at a distance of about 110 million light years
from the solar system, IC 4633 (3 x 4 arcminutes) is classified as type Sc and
IC 4633 (3 x 0.7 arcminutes) as Hubble SBb type. Furthermore, our image shows
some faint galaxies from the Leda and PGC catalogue. A distance of MW 9 to the
solar system is not known.
Further
Informationen: A nice description (german language only) of the
constellation Pavo
can be found here. For the project of photographing IFNs by
Steve Mandel a pdf-file in download
here.
« Click here or on the thumbnail to load a large image with
object names and size comparison to the moon. |
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All Images und all Content are ©
by Franz Hofmann + Wolfgang Paech |